Coating cutting tools with hard substance lowers friction co-efficient and improves tool life - a review

Abstract

Abstract— Many papers have been presented before which show coating of cutting tools often yield decreased wear rates and reduced coefficients of friction. Although different theories are proposed in those literatures covering areas such as; hardness theory, diffusion barrier theory, thermal barriertheory, reduced friction theory, most have not dealt with the question of how and why coating of tool substrates with hard material such as Titanium Nitride (TiN), Titanium Carbide (TiC) and Aluminium Oxide (AL203) transforms the performance of cutting tools. The paper discusses the complex interrelationship that encompasses the thermal barrier function and the relatively low sliding friction coefficient of TiN. It concludes by saying that, the coating on tools lowers the friction coefficient and increase wear resistance long after the original coating-substrate interface, has been penetrated. Index Terms—Friction Coefficients, Coating, Wear Resistance